16625809 has 2 divisors, whose sum is σ = 16625810. Its totient is φ = 16625808.

The previous prime is 16625789. The next prime is 16625831. The reversal of 16625809 is 90852661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 1392400 = 3903^2 + 1180^2 .

It is a cyclic number.

It is not a de Polignac number, because 16625809 - 2⁷ = 16625681 is a prime.

It is not a weakly prime, because it can be changed into another prime (16625009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8312904 + 8312905.

It is an arithmetic number, because the mean of its divisors is an integer number (8312905).

Almost surely, 2^16625809 is an apocalyptic number.

It is an amenable number.

16625809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16625809 is an equidigital number, since it uses as much as digits as its factorization.

16625809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 16625809 is about 4077.4758123133. The cubic root of 16625809 is about 255.2275758978.

The spelling of 16625809 in words is "sixteen million, six hundred twenty-five thousand, eight hundred nine".